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<h2>Discussion</h2>
<br><br>
EAN-13 is a superset of UPC-A that is more globally friendly. To add support for more countries, an additional digit
had to be added (13 as opposed to UPC's 12), but to make it backward compatible with UPC-A, this extra digit is encoded
not in the bars directly but in the parity of the other encoded letters. For UPC-A values, a zero is prepended to the
content, and the character parity is the same as specified in the UPC-A specs.
<br><br>
We need to override content, digitsToRight, and rightCaption because EAN display the characters slightly differently
than UPC-A (1 to the left, 6 digits on each side of the center guard bars, none to the right). We also need to override the
method barcode to deal with the increased parity options of EAN.
 <hr><br><p>(Last Updated 4/21/2003)
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